U. S. Pat. No. 4,771,902 issued to the same applicant of this application discloses a container having a bottleneck inversely mounted on a base packed by a bell-shape sealer made of elastomer materials, of which the sealer includes plural annular extension rings concentrically circumferentially formed on an inside wall of the sealer, adapted to be turned up along the bottleneck to pack the bottle-neck tightly in a base when inversely mounting the container on the supporting base.
However, such a container, when filled with water and subjected to a temperature below zero degree centigrade, may be broken since the inside water is frozen to expand its volume to cause breakage of a glass container, especially when transported in a very cold weather.
The present inventor has found the defects of the original invention and invented the present sealer having a buffer effect especially for a cold temperature.